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Yakvenalex [24]

1 year ago

6

Calculate the amount of heat necessary to raise the temperature of 135.0 g of water from 50.4°F to 85.0°F. The specific heat of

water = 4.184 J/g·°C.

1 answer:

MAXImum [283]1 year ago

6 0

Here we have to calculate the heat required to raise the temperature of water from 85.0 ⁰F to 50.4 ⁰F.

10.857 kJ heat will be needed to raise the temperature from 50.4 ⁰F to 85.0 ⁰F

The amount of heat required to raise the temperature can be obtained from the equation H = m×s×(t₂-t₁).

Where H = Heat, s =specific gravity = 4.184 J/g.⁰C, m = mass = 135.0 g, t₁ (initial temperature) = 50.4 ⁰F or 10.222 ⁰C and t₂ (final temperature) = 85.0⁰F or 29.444 ⁰C.

On plugging the values we get:

H = 135.0 g × 4.184 J/g.⁰C×(29.444 - 10.222) ⁰C

Or, H = 10857.354 J or 10.857 kJ.

Thus 10857.354 J or 10.857 kJ heat will be needed to raise the temperature.

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Two species, A and B, are separated on a 2.00 m long column which has 5.000 x 103 plates when the flow rate is 15.0 mL/min. A sp

sergiy2304 [10]

Explanation:

The given data is as follows.

$t_{m}$ = 30.0 sec, $t_{r1}$ = 5 min = $5 \times 60 sec$ = 300 sec

$t_{r2}$ = 12.0 min = $12 \times 60 sec$ = 720 sec

Formula for adjusted retention time is as follows.

$t'_{r} = t_{r} - t_{m}$

= 300 sec - 30.0 sec

= 270 sec

$t'_{r2}$ = 720 sec - 30 sec

= 690 sec

Formula for relative retention ( $\alpha$ ) is as follows.

$\alpha = \frac{t'_{r2}}{t'_{r1}}$

= $\frac{690 sec}{270 sec}$

= 2.56

Thus, we can conclude that the relative retention is 2.56.

4 0

2 years ago

A 75 lb (34 kg) boy falls out of a tree from a height of 10 ft (3 m). i. What is the kinetic energy of the boy when he hits the

Jobisdone [24]

Answer:

Kinetic energy of boy just before hitting the ground is $\approx$ 1000 J.

Speed of boy just before hitting the ground is 7.67 m/s

or 17.16 mi/hr.

Explanation:

Given that:

Mass of boy = 75lb = 34 kg

Height, h = 10ft = 3m

To find:

Kinetic energy of boy when he hits the ground.

<em>As per law of conservation of energy The potential energy gets converted to kinetic energy.</em>

<em></em>

<em></em> $\therefore$ <em> </em>Kinetic energy at the time boy hits the ground = Initial potential energy of the boy when he was at the Height 'h'

The formula for potential energy is given as:

$PE = mgh$

Where m is the mass

g is the acceleration due to gravity, g = 9.8 $m/s^2$

h is the height of object

Putting all the values:

PE = $34 \times 9.8 \times 3 \approx 1000\ J$

Hence, Kinetic energy is $\approx$ 1000 J.

Formula for Kinetic energy is:

$KE = \dfrac{1}{2}mv^2$

where m is the mass and

v is the speed

Putting the values and finding v:

$1000 = \dfrac{1}{2}\times 34 \times v^2\\\Rightarrow v^2 = 58.82\\\Rightarrow v = 7.67\ m/s$

Given that:

1 m = 1.094 yd and 1 mi = 1760 yd

$\Rightarrow 1609\ m = 1\ mi$

Converting 7.67 m/s to miles/hour:

$\dfrac{7.67 \times 3600}{1609}=17.16\ mi/h$

4 0

2 years ago

Suppose you are titrating vinegar, which is an acetic acid solution of unknown strength, with a sodium hydroxide solution accord

Marina CMI [18]

Answer:

$M_{acid}=0.563M$

Explanation:

Hello there!

In this case, given the neutralization of the acetic acid as a weak one with sodium hydroxide as a strong base, we can see how the moles of the both of them are the same at the equivalence point; thus, it is possible to write:

$M_{acid}V_{acid}=M_{base}V_{base}$

Thus, we solve for the molarity of the acid to obtain:

$M_{acid}=\frac{M_{base}V_{base}}{V_{acid}} \\\\ M_{acid}=\frac{33.98mL*0.1656M}{10.0mL}\\\\ M_{acid}=0.563M$

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5 0

2 years ago

Why are metallic crystals malleable and ductile? A. The electrons are free floating, allowing them to move with the atoms when t

jok3333 [9.3K]

Answer:

D. The atoms are arranged with alternating positive and negative charges. When struck, the lattice shifts putting positives against positives and negatives against negatives.

Explanation:

Metallic crystals takes their properties as a result of metallic bonds in between the atoms.

Metallic bond is actually the attraction between the positive nuclei of all the closely packed atoms in the lattice and the electron cloud jointly formed by all the atoms by losing their outermost shell electrons this is by virtue of their low ionization energy.

Physical properties of metals such as malleability, ductility, electrical conductivity, etc can be accounted for by metallic bonds.

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2 years ago

When 28.0 g of acetylene reacts with hydrogen, 24.5 g of ethane is produced. What is the percent yield of C2H6 for the reaction?

Afina-wow [57]

Answer:

$Y=75.6\%$

Explanation:

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In this case, since no information about the reacting hydrogen is given, we can assume that it completely react with the 28.0 g of acetylene to yield ethane. In such a way, via the 1:1 mole ratio between acetylene (molar mass = 26 g/mol) and ethane (molar mass = 30 g/mol), we compute the yielded grams, or the theoretical yield of ethane as shown below:

$m_{C_2H_6}^{theoretical}=28.0gC_2H_2*\frac{1molC_2H_2}{26gC_2H_2}*\frac{1molC_2H_6}{1molC_2H_2} *\frac{30gC_2H_6}{1molC_2H_6}\\ \\m_{C_2H_6}^{theoretical}=32.3gC_2H_6$

Hence, by knowing that the percent yield is computed via the actual yield (24.5 g) over the theoretical yield, we obtain:

$Y=\frac{24.5g}{32.3g}*100\%\\ \\Y=75.6\%$

Best regards.

3 0

2 years ago